AirSpaceMag.com

The Next Little Thing

Why 2006 is the year of the very light jet.

Honda's in! As announcements go, this was a whopper. More than 15 years of development preceded Honda's decision, trumpeted at this year's Oshkosh, Wisconsin fly-in, to build the HondaJet. Most attentive listeners? Other jet builders.
(American Honda Motor Co.)

At the world’s largest gathering of propeller-driven airplanes, this year’s big news was jets. A whole new class of jet aircraft, very light jets, dominated the general aviation exhibits at the Experimental Aircraft Association’s Oshkosh, Wisconsin airshow. No fewer than seven companies—Adam, ATG, Cessna, Diamond, Eclipse, Embraer, and Honda—had little jets, or mock-ups of them, on display, and there was buzz at every booth.

As a class, VLJs incorporate significant advances in airframe design, engines, computerized avionics, manufacturing techniques, and materials. The advances, developed mainly over the last decade, make these small aircraft easier to operate than jets of the previous generation and—even with jet fuel now hovering around $4 a gallon—more affordable to fly. The new class consumes half the fuel that older corporate jets do, so many more pilots can afford to own jets today than could a decade ago. The Federal Aviation Administration predicts that 4,500 light jets will be flying by 2016. (To put the potential impact of VLJs in perspective, consider this: There are 15,000 business jets currently operating worldwide, and Cessna, the most prolific manufacturer of them, plans to deliver 290 this year.) When FAA Administrator Marion Blakey awarded the Eclipse Model 500 provisional certification at Oshkosh last July—timing that contributed to the fanfare—she said, “This is a real game-changer for our industry.”

The rules of that game actually began changing as early as 1970, when Cessna introduced the Citation, a “slow” 400-mph jet that made it possible for pilots who had been flying 300-mph twin turboprops, like the popular Beech King Air, to step up. Transitioning to a 100-mph-faster airplane that could fly about 10,000 feet higher than the airplanes private pilots were accustomed to wouldn’t demand as much training (or money) as would be required to fly the 500-mph jets with 40,000-foot ceilings that populated the inventory at the time (see “Getting Up to Speed,” p. 56). Within a decade, the Citation stole much of the twin turboprop market. Today, Cessna Citations account for one-third of all new business jet sales. (Cessna has also jumped into the very light jet market with its six-seat, 390-mph Citation Mustang, which is on track for certification later this year, but CEO Jack Pelton resists calling it a VLJ; rather, he labels it a “downward expansion of the product line.”) The Citation brought more pilots into the jet fold. Enticing even more would mean finding the next niche: a jet even cheaper and easier to operate than the Citation.

While the Citation was causing a small upheaval in business aviation, engine maker Sam Williams was working on small turbofans, the least fuel-hungry type of jet engine operating today, to power cruise missiles. Williams believed the little engines might create the next general aviation niche. “He always thought anyone who could fly would prefer to fly a jet,” says Matt Huff, vice president of business development for Williams International. Huff says that the turbofan technology developed for cruise missiles did not directly carry over to the family of powerplants Williams eventually designed for today’s VLJs, but adds, “We did learn an awful lot of lessons from the cruise missile program that helped us when we decided to go into general aviation.”

An interim step was the 2,300-pound-thrust FJ-44 turbofan. The engine entered commercial service in 1993 and to date Williams has produced 2,400.

But Williams believed the real production increases would come when a significant percentage of private pilots flying piston-powered twin-engine aircraft (18,469 airplanes in the United States, according to the FAA) could transition into a new category of light jets. In 1996, the company partnered with NASA’s General Aviation Propulsion Program. Conducted by the Glenn Research Center in Ohio, the program was one of several NASA-sponsored efforts to revitalize the sagging U.S. general aviation industry. Williams said in a company press release the following year: “Our objective is to replace aging, piston-powered light aircraft with all new, four-place single and six-place twin, turbofan-powered modern aircraft. This means we must develop a turbofan in the 700-pound thrust category that is very low in cost at a high production rate, is extremely quiet, is light in weight, and is very reliable.”

Williams had hired Burt Rutan to build a demonstration aircraft, the V-JET II, to showcase his new engine. The V-JET, looking the part of the revolutionary, made its first public flight at Oshkosh in 1997. Built of composite materials, the aircraft had a V tail, a nose shaped like a fighter’s, forward-swept, drooping wings, and a portal windshield. It was extremely quiet thanks to the pair of experimental 550-pound-thrust, low-pressure Williams FJX-1 engines it was built for.

One of the first true believers the V-JET called to the cause was Vern Raburn, today the CEO of Eclipse Aviation. Raburn, a 7,000-hour jet-rated pilot who had held senior executive positions at Microsoft, Lotus Development, Symantec, and Slate, founded Eclipse in 1998 after several discussions with Sam Williams. The company’s original engineering team was for a time housed at Williams’ headquarters.

The Eclipse-Williams relationship soured in 2002 after the 700-pound-thrust EJ-22 engine, a descendant of the V-JET’s FJX-1, suffered repeated flight test failures (see “The Little Engine That Couldn’t,” Feb./Mar. 2005). However, by then Williams already had developed an 80-percent-scale version of its FJ-44 corporate jet engine. The new FJ-33 weighs just 300 pounds and delivers 1,000 to 1,500 pounds of thrust. It incorporates advances pioneered on the FJ-44, including scalloped exhaust pipes that reduce engine noise and widely swept and rounded fan blades, which contribute to lower noise and better fuel economy.

To date, the FJ-33 has been selected to power four VLJ designs seeking FAA certification: Adam A700, ATG Javelin, Diamond D-JET, and Spectrum 33.